Tourists, backpackers help global spread of large widow spiders, says top researcher

Source: Xinhua| 2019-02-26 06:11:02|Editor: yan
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LONDON, Feb. 25 (Xinhua) -- Tourists are playing a part in a rapid global spread of a large spider species resembling the black widow which poses a threat to native spiders, scientists in Britain and Germany said on Monday.

The Noble False Widow, Steatoda nobilis, native to Madeira and the Canary Islands, has been hitching a ride in camper vans and cars, and even on the clothes of backpackers.

Researchers from the University of Manchester, German State Museum of Natural History Karlsruhe and Trier University scientists have published their findings in the latest edition of the journal NeoBiota.

They say that after a long period of stasis the spider has recently started to appear in the North of England, as well as in new locations in countries around the world. It has been present in the south of England for more than a hundred years.

"The most likely scenario is spiders hitching a lift on your car or camper van, travelling back home. One of the new records from the Netherlands, that we describe in our paper, was found near several camping sites, supporting this idea," Biologist Professor Rainer Breitling from the University of Manchester, explained the spread to Xinhua.

If vacationers stay outdoors a lot, they might also pick up spiders on clothes or backpacks. And they could spread them by bringing back plants as souvenirs as well, the professor added.

The researchers said the spread to Britain and Ireland has caused panic when false widows have been found in large numbers in schools and other public spaces.

"Although its bite can be very painful, comparable to a severe bee or wasp sting, there are no confirmed cases of serious medical consequences from a Noble False Widow bite, said Breitling.

However, he admitted, "the intense public interest created by sometimes rather exaggerated media coverage is now helping our research."

Breitling said members of the public have been contributing their observations to a large dataset of False Widow records for the British Arachnological Society's Spider Recording Scheme.

In their academic paper, the researchers describe how they used use computer modelling to predict favorable habitats for future false widow invasions, based on present occurrence patterns.

The model successfully predicted that the species would be found in Normandy, France, which was confirmed after a field trip to the area.

Mediterranean islands, southern Australia, large parts of New Zealand and South Africa also seem to be likely targets for future expansion.

"These are areas that are home to a wide range of vulnerable native species, so the potential introduction of Steatoda nobilis, which can overcome prey much larger than its own size, is quite worrying," Breitling noted.

"We think that it's likely that these animals get about by hitching a lift on of ornamental plant trade or tourism, rather than banana imports as has been previously thought. So more careful monitoring of plant imports could be useful to control the spread of this species and other invasive spiders."

The University of Manchester has long been a hotspot of spider research in Britain and is home to one of the most diverse spider collections at the Manchester Museum.

Researchers at the university are working on topics ranging from fossil spiders in amber to the mating dances of jumping spiders to the use of bacteria-produced spider silk for biotechnology.